VEHICLE ENGINE OPERATION
First Claim
1. A system for detecting an operating state of a vehicle engine, the system comprising:
- an input for coupling in a signal from a power line of a vehicle;
means to filter out relatively high frequency transient noise components of a signal received from the power line;
a first detector for receiving the filtered signal and detecting when transient noise associated with the power line rises above a first threshold and generating a first detection signal in response thereto;
a second detector for receiving the filtered signal and detecting when the transient noise falls below a second threshold, which is lower than the first threshold, and generating a second detection signal in response thereto; and
means for generating a first output signal in response to the first detection signal and a second output signal in response to the second detection signal.
3 Assignments
0 Petitions
Accused Products
Abstract
Disclosed is a system for detecting an operating state of a vehicle engine, for example, in order to arm or disarm a vehicle alarm system. The system comprises: an input coupled to a power line of a vehicle; means to filter out relatively high frequency transient noise components of a signal received from the power line; a first detector for receiving the filtered signal and detecting when transient noise associated with the power line rises above a first threshold and generating a first detection signal in response thereto; a second detector for receiving the filtered signal and detecting when the transient noise falls below a second threshold, which is lower than the first threshold, and generating a second detection signal in response thereto; and means for generating a first output signal in response to the first detection signal and a second output signal in response to the second detection signal.
26 Citations
14 Claims
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1. A system for detecting an operating state of a vehicle engine, the system comprising:
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an input for coupling in a signal from a power line of a vehicle; means to filter out relatively high frequency transient noise components of a signal received from the power line; a first detector for receiving the filtered signal and detecting when transient noise associated with the power line rises above a first threshold and generating a first detection signal in response thereto; a second detector for receiving the filtered signal and detecting when the transient noise falls below a second threshold, which is lower than the first threshold, and generating a second detection signal in response thereto; and means for generating a first output signal in response to the first detection signal and a second output signal in response to the second detection signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification